Dowels are embedded into joints between adjacent slabs of concrete to prevent vertical displacement between the slabs to maintain a smooth pavement surface and increase the strength of the concrete in the region of the joint. While the dowels are embedded in the joints to prevent excessive vertical displacement between the slabs, they may be designed to allow a small amount of horizontal separation as well as vertical and lateral displacement between the slabs to relieve internal stress to accommodate drying shrinkage and thermal expansion and contraction of the slabs. This permits a normal amount of slab movement to prevent excessive cracking while still maintaining a sufficiently smooth top surface of the pavement.
In pavement construction, a series of dowels is typically installed at each expansion joint between adjacent sections or slabs of pavement. A long structure known as a dowel basket is typically used to hold a line of dowels in place at the edge of a section of pavement before the slab is poured. The basket positions each dowel so that half of the dowels will be embedded in the concrete slab to be poured, with the other half to be embedded in the adjacent slab to be poured next. An expansion joint is typically formed into the joint or cut into the dried concrete above the dowel basket at each expansion joint. The pavement is thus constructed section after section, and in some cases mile after mile, with a line of dowels held in place by a dowel basket embedded into the concrete at each expansion joint. A range of pavement structures are constructed in this manner, such as roads, bridges, sidewalk, floors, buildings, and so forth. The term “pavement” for this purpose includes walls, roofs, ceilings, caisson, and other structures as well as roads, bridges, floors and sidewalks. Pavement is typically manufactured from form concrete, but may be made from any suitable material poured in sections.
Constructing a road in this manner requires the dowel baskets to be continually manufactured and made available at the construction site as section after section, and mile after mile, of road is poured. In conventional road construction, the dowel baskets are welded together at a welding shop and then transported, typically by truck, to the construction site. For a long road construction project, a series of welding jobbers may be contracted along the route as the road is constructed. Dowel basket fabrication can be a significant logistical challenge and a major cost factor in road construction. A similar concern can arise in any project utilizing large numbers of joined concrete pavement sections, such as high-rise buildings, sidewalks, bridges, dams, and so forth. At times, dowel basket fabrication may become the critical path item, causing construction crews to sit idle waiting on dowel basket delivery before construction of the project can continue. As a result, there is a persistent need for cost effective solution to dowel basket manufacturing to facilitate concrete pavement construction.